1. Field of the Invention
The present invention relates to a gas generator for use in a restraining device of a vehicle and the like.
2. Description of Related Art
In a gas generator that uses a solid gas generating agent, a gas generating agent of various shapes such as granular, a pellet form and a disk shape is used. The surface area of a gas generating agent increases when the agent is powdered due to external vibration or shock, which affects the output of the gas generator. Thus, fixing means for the gas generating agent is needed in order to block movement of the gas generating agent in the combustion chamber.
In JP-A No. 2002-503584, an igniter cup 56 and a generant cup 84 are aligned in the radial direction in a housing construction 12. A second gas generant material 86 and an initiating device 90 are accommodated in a second chamber 82 in the generant cup 84. A plurality of gas exit orifices 104 are formed on a sidewall 100 of the generant cup 84, and an outer side wall of the cylindrical sidewall 100 including the gas exit orifices 104 is covered with a cylindrical pressure sensitive insulator barrier material 106.
As shown in FIG. 1, a first gas generant material 36 in a first chamber 34 is retained by a retainer 50, and the retainer 50 further presses a part of the pressure sensitive insulator barrier material 106. Since the other portions of the pressure sensitive insulator barrier material 106 are sandwiched with the igniter cup 56 and the generant cup 84, it is impossible to expand and deform in the direction of the igniter cup 56, and it is difficult for the gas exit orifices 104 of the generant cup 84 which face the igniter cup 56 to open. In addition, since the retainer 50 abuts against an upper surface of a filter 42, an charging amount into the first chamber 34 is restricted, so in some cases, the function of retaining the gas generant cannot be sufficiently yielded depending on an amount of the first gas generant 36.